Addressing the context, though, Baltimore certainly belongs in any discussion of unpleasant downtowns. Altercations are a potential issue even driving (more so than walking actually). But there's also increasingly little to even walk to. The nightlife and culture all moved to the surrounding neighborhoods, now you just go downtown for the aquarium or the occasional bureaucratic necessity.
are you referring to the complimentary car wash at president and lombard? but yeah I agree, there's a lot that's wrong with baltimore's downtown.
if you assume that most people have to commute to work, it does make sense to have a downtown that's mostly office buildings and well-connected via public transit. so I kinda expect most downtowns to be kinda boring, not sure why you would expect them to be fun to walk around it. of course, nowhere in baltimore is particularly well-served by public transit, and the downtown is not merely boring; it's downright unpleasant and somewhat unsafe.
I guess you could imagine restaurants switching from lunch to dinner service, but yeah the whole idea of downtown lends itself to emptiness I guess. Certainly not helped in Baltimore's case by how many of the offices are just empty.
for one thing, it depends a lot on how city borders are drawn. for example, baltimore city usually shows up in top five lists for per capita murders, and indeed it is an unusually violent place. but unlike many (most?) american cities, baltimore county is completely separate from the enclosed city. if you calculated murders per capital for baltimore city and county as a single population, it would still be bad, but it wouldn't be in the national top five every year. a corollary to this is that murder rates can vary much more neighborhood-to-neighborhood within the same city than they do when comparing entire cities. most cities I've been to have at least one or two dangerous areas to be avoided if possible.
second point: even in "dangerous cities" upper-middle class professionals are unlikely to be victims of violent crime. they generally choose to live in safer enclaves of those cities. realistically, property crime is a greater concern for this demographic, which does not scale linearly with violent crime and is not restricted to the "bad neighborhoods" the same way. interestingly, "safe" cities like seattle and SF actually have higher rates of property crime than baltimore.